Posted by Sherman in Idaho [50.120.88.57] on Sunday, October 04, 2015 at 13:41:19 :
In Reply to: Re: 3500/7000 Watt Inverter Pict posted by Mike in Pa. [24.3.201.232] on Saturday, October 03, 2015 at 21:40:44 :
It will be enough for most use. I've run a lot of power tools off of similar inverters and as a rule, if you keep the battery fully charged (the inverters cut out abruptly if the voltage drops much at all), that kind of inverter is good for full use of most portable electric tools. It will struggle to run a worm-drive Skil saw, because they draw so much start-up current, and it won't run a roto-hammer drilling 1-1/2" holes in rock, but for a heavy duty drill, chop saw, sawzall, direct-drive skil saw, etc, it's fine.
The trouble with inverters is that there's an absolute hard limit on how much current they can put out. Ask for anything above that, and you get zero. Likewise, if the input voltage drops below the allowed level, even momentarily, everything stops. In short, they don't handle surges well at all. A gas-powered generator, on the other hand, will easily handle brief surges because the rotating mechanism has lots of inertia and the short-term generating capacity is just a matter of the resistance of the wire in the windings and the amount of iron in the laminations. You can overload it severely for a faction of a second without damaging anything or stalling the motor.
I think the point having a built-in inverter on a truck is for convenience that will handle 90% of the electric tasks you need, not to have something so powerful that it will handle absolutely anything you might ever want to do. For that, you need a PTO-powered generator, like on the old welding trucks and military shop vans.